USE master

IF EXISTS
	(SELECT name
		FROM sys.databases
			WHERE name = 'db_World')
BEGIN
	DROP DATABASE db_World
END

CREATE DATABASE db_World;
GO

USE db_World

IF OBJECT_ID('dbo.tbl_Persons', 'U') IS NOT NULL -- The 'U' for the second param apparently means "Only look for objects with this name that are tables".
BEGIN
	DROP TABLE tbl_Persons
END

CREATE TABLE tbl_Persons
(
	person_id INT NOT NULL IDENTITY(1, 1) PRIMARY KEY,
	person_firstName NVARCHAR(20) NOT NULL,
	person_lastName NVARCHAR(20) NOT NULL,
	SSN NVARCHAR(30) NOT NULL UNIQUE,
)
GO

IF OBJECT_ID('dbo.tbl_Accounts', 'U') IS NOT NULL
BEGIN
	DROP TABLE tbl_Accounts
END

CREATE TABLE tbl_Accounts
(
	account_id INT NOT NULL IDENTITY(1, 1) PRIMARY KEY,
	account_personId INT NOT NULL,
	CONSTRAINT account_FK_personId FOREIGN KEY (account_personId) REFERENCES tbl_Persons(person_id),
	account_balance MONEY
)
GO

INSERT INTO tbl_Persons VALUES ('Peter', 'Petrov', '123-123-123')
INSERT INTO tbl_Persons VALUES ('Ivan', 'Ivanov', '321-321-321')

INSERT INTO tbl_Accounts VALUES (1, 333)
INSERT INTO tbl_Accounts VALUES (2, 999)
GO